This invention relates generally to systems for vehicle toll collection, and, more particularly, relates to apparatus and methods for automatic, non-contact, high-speed collection of vehicular tolls.
An increasing number of vehicles are traveling over progressively more congested highways. The collection of tolls by conventional means has had a negative effect upon highway throughput and safety. Congestion and long backups on toll plazas are becoming more common. Such conditions involve a significant economic cost, through lost time, and reduced productivity. Moreover, serious accidents at toll plazas, caused by operator or mechanical failure, have also increased in frequency.
Certain toll authorities have attempted to respond to these problems by providing coin-operated toll collection devices, or by instituting a toll-plate system in which toll-takers visually inspect each incoming vehicle for an appropriate toll plate or sticker. Coin-operated toll collection systems, however, do little to increase throughput, and are susceptible to fraud, through the use of counterfeit coins. Toll-plate systems suffer the same deficiencies, requiring each vehicle to slow sharply while entering the visual inspection area; these systems also rely heavily on toll-taker attentiveness.
Additionally, a number, of systems have been proposed for utilizing radio frequency identification (RFID) techniques for toll collection. Under these systems, drivers acquire a “tag” or card that acts as a reflective transmitter or discrete transmitter to identify the vehicle by serial number as it passes through a toll booth. This technique is also referred to as Automatic Vehicle Identification (AVI).
This system also suffers from a number of deficiencies. In particular, because the RFID tag lacks a machine-intelligent processor for manipulation and storage of accounts, toll authorities must maintain individual toll accounts for all users of the system. This becomes especially burdensome in urban areas or regions of high toll traffic volume. Toll agencies would need to manage hundreds of thousands of individual accounts, a burden that is created by operation of the AVI system.
Additionally, because the RFID tags lack a processor or user interface, vehicle operators cannot readily ascertain account balances, and have no warning as to limited or exhausted credit. This creates both confusion, and potential safety hazards, as drivers cross over to conventional toll collection lanes with little warning.
Further, in the absence of a single national toll agency, each participating driver would need to have multiple cards attached to the vehicle, each corresponding to a separate toll authority account.
The RFID system also raises user-privacy issues by requiring the generation and storage of detailed vehicle-specific travel records.
In response to the inability of conventional toll collection means to meet the demands created by increased highway traffic, automated toll facilities that provide improved toll collection methods and systems have been proposed. These automated toll facilities eliminate the manual transactions of conventional toll collection means through the use of radio transmitters and receivers that perform the necessary transactions as a vehicle travels through the automated toll booth. One such system electronically collects tolls from an electronic cache of toll credits carried within the vehicle. In this way, a vehicle operator can purchase a quantity of toll credits-prior to traveling on a toll road. As the vehicle later travels through a toll collection booth, a radio-frequency exchange occurs and the appropriate amount is automatically debited from the vehicle's toll credits.
Although the automated toll collection system described above functions well for single lane toll roads or single lane bridges and tunnels, a significant problem can exist when the system is practiced in a multi-lane environment. In a multi-lane environment, each toll lane is equipped with a stationary radio-transceiver to interact with the mobile radio-transceiver of vehicles passing through that lane. The problem of multi-pathing occurs when information transmitted from a vehicle in one lane is picked up by multiple toll lane stationary transceivers. Therefore the possibility exists that a toll collected from a vehicle in lane 1 may be credited to the vehicle in lane 2. The effect of multi-pathing allows toll-evaders to exploit automated toll systems, as well as accidentally misallocating the debits.
A number of prior art systems exist that minimize the effects of multi-pathing. These systems typically attempt to shield the toll transceiver of one lane from signals transmitted from mobile units traveling in an adjacent lane. Such systems include methods that establish a proximity zone that identifies when a vehicle has entered a predetermined region, and then requires the vehicle to transmit the toll within a predetermined time limit. Other systems establish a multi-field environment, where a blanking field is transmitted behind and adjacent to a region proximate to the toll lane. The blanking zone serves to swamp out any multi-path signals that could be received by the toll station. The prior art systems do not provide a means for determining the actual lane position of an oncoming mobile unit. Because of this, the prior art systems do not allow the toll system to determine the physical sequence of oncoming traffic approaching the toll system. Moreover, the prior art systems place constraints on the size of the lanes and the spacing that must exist between each lane transceiver.
It is accordingly an object of the invention to provide improved toll collection methods and apparatus that significantly increase the traffic capacity of roadways.
Another object of the invention is to provide toll collection methods and apparatus that increase the rate of toll collection while enhancing highway safety.
A further object of the invention is to provide such methods and apparatus that are convenient to use and support toll collection by a plurality of toll authorities or authorities at a plurality of widely separated locations.
Yet another object of the invention is to provide toll collection systems that reduce administrative burdens, facilitate the generation of transaction reports for users and toll authorities, and preserve the privacy of users.
It is a further object of the invention to provide toll collection systems that are reliable and resistant to attempts at fraud or toll evasion, and which are readily integrated into existing toll management systems.
Another object of the present invention is to provide a system for determining the lane position of a vehicle approaching an automated toll system.
A further object of the invention is to provide a mechanism for determining the sequence of mobile units approaching an automated toll system.
An additional object of the invention is to provide a system for determining the relative position of a mobile object approaching a stationary transceiver.
And yet another object of the invention is to provide a system for automatic toll collection that uses toll transceivers that can work in close proximity with other toll transceivers.
Other general and specific objects of the invention will in part be obvious and will in part appear hereinafter.